CONCHOLOGY. 



375 



dom had swelled to 1327 pages. This edition was 

 published about ten years after Adanson's work, the 

 perusal of which had probably somewhat modified 

 the views of Linnaeus. Linnaeus divides his sixth 

 class of animals into five orders, in the second of 

 which are eight genera of true mollusca, viz., ascidia, 

 Umax, aplysia, doris, tethys, sepia, clio, and scylleea. 

 The third order is almost entirely devoted to testa- 

 cea,* divided into, 1. multivalves, the shell hav- 

 ing more than two pieces ; 2. bivalves, having two 

 pieces ; 3. univalves, having one piece. The first 

 division contains three genera, chiton, lepas, and pho- 

 lat. The second contains fourteen genera ; mya, 

 solen, tellina, cardium, mactra, donax, venus, spondy- 

 lus, chama, area, ostrea, anomia, mytilus, and pinna. 

 The third division, separated into two sections, ac- 

 cording as the spire is regular or not, contains nine- 

 teen genera argonauta, nautilus, conus, cyprcea, bul- 

 la, valuta, buccinum, strombus, murex, trochus, turbo, 

 helix, nerita, haliotis, patella, dentalium, sergula, te- 

 redo, and sabella. In giving the characters ot his gen- 

 era, with respect to the animals, Linnaeus is always 

 satisfied with citing the name of a naked molluscum 

 described in the preceding order, which he supposes 

 to be analogous to the animal of the genus under 

 consideration ; therefore it is probable that the influ- 

 ence exerted by Adanson's work over the latter edi- 

 tions of the Sy sterna Naturae extended only to increas- 

 ing the number of genera, and causing them to be 

 more rigorously marked out and described. Some 

 of the approximations of the Linnaean system are un- 

 natural and inconvenient, and some genera, nearly 

 related, are too far separated in the arrangement ; 

 but its nomenclature, and the clearness and precision 

 of its technical terms, gave it a predominance that it 

 lias maintained almost to the present day. A detail- 

 ed explanation of the conchyliological system of Lin- 

 naeus may be found in a dissertation by I. Murray, 

 published hi the eighth volume of the Academical 

 Amenities. 



The Neuet systematisches Conchylien Kabinet a 

 great work commenced by Martini in 1769, continu- 

 ed by Chemnitz, and finished by Schroter in 1793 

 may be considered rather as a magnificent collection 

 of figures of shells, well drawn and coloured, than as 

 a system of conchyliology. As its figures are constant- 

 ly referred to by the modern authors, it will be found 

 very useful to students in identifying species and ar- 

 ranging their cabinets. The whole work consists of 

 12 volumes 4to. In 1776, Da Costa published his 

 Elements of Conchology, in which more attention 

 was paid by him to the characters of the aperture in 

 univalves, and to the hinge in bivalves, than had been 

 done by his predecessors ; and the science is indebt- 

 ed to him for some valuable hints on the indelicacy 

 of some of the terms employed by Linnaeus to desig- 

 nate particular parts of bivalve shells. In 1766, Pal- 

 las had published his Miscellanea Zoologica, the prin- 

 ciples of which, perhaps, entitle him to be considered 

 as the founder of that new school which the French 

 conchy liologists have since so successfully supported. 

 He indicated the impropriety of separating the testa- 

 cea from the naked mollusca, in the arrangement of 

 Linnaeus, and showed that a natural method could 

 only arise from the consideration, not of the shells, 

 hut of the generic differences of the animals inhabit- 

 ing them. 



Notwithstanding the light struck out by Pallas, 

 Bruguidre, one of the modern authors to whom the 

 science is most indebted, in 1792, still followed so 

 closely the Linnaean arrangement as to admit the di- 



* As Linnaeus has said so little about the animals, if we 

 translate teitacea by the term thelli, perhaps the error will 

 be scarcely appreciable. 



vision of the molluscous worms and testaceous worms 

 into two orders. His order testacea is nearly the 

 same as that of Linnaeus, except that the genera are 

 somewhat more numerous and better defined. This 

 order contains three divisions, according to the num- 

 ber of the valves. He divides the genus lepas of Lin- 

 naeus into balanus and anatifa, dropping the term 

 lepas altogether, in which he has been followed by 

 Lamarck. This is so unusual, and, indeed, so un- 

 gracious a proceeding, that we would recommend to 

 American conchyliologists always to use the term 

 lepas instead of anatifa. Besides the two genera 

 above-mentioned, he places among the multivalves, 

 chiton, teredo, fistulana, pholas, anomia, and crania. 

 Among the bivalves, his new genera are, placuna, 

 perna, trigonia, unio, tridacna, cardita, and terebratu- 

 la. Among his univalves are the following new 

 genera : fissurella, siliquaria,aspergillum, ovula, oliva, 

 purpura, cassis, terebra, fusus, cerithium, bulimia , 

 planorbis, natica, camerina, ammonites, and orthocera. 



In 179 1 appeared the first volume of Testacea utri- 

 usque Sicilice, eorumque Historia et Anatome a splen- 

 did work, by Poli, an Italian physician, who first at- 

 tempted to establish the genera of mollusca from the 

 consideration of the animal only, without reference 

 to the shell. This work may be considered as form- 

 ing a remarkable epoch in the science, because, since 

 its appearance, the classification of the mollusca and 

 of the bivalves has become much more conformable 

 to nature. The subjects figured in the superb plates 

 of this work had been previously modelled in wax 

 by the scholars of the author. In 1798, G. Cuvier 

 proposed a new classification of molluscous animals. 

 (Tableau elementaire de I'Histoire naturelle des Ani- 

 maux.) In this, he acknowledged himself indebted to 

 the critical observations of Paflas, and carried nearer 

 to perfection the inventions of Poli. In this arrange- 

 ment, also, may be found the improvements succes- 

 sively introduced by Brugui^re into the distinction of 

 genera, which Lamarck was then increasing every 

 year, in his course at ttiejardin du rot. 



Lamarck did not begin to publish the results of 

 his labours, until 1798, when a memoir on the divi- 

 sion of the genus sepia into three genera sepia, loligo 

 and octopus, appeared in the Journ. d'hist. Nat., t. 

 1. Early in 1799, Lamarck published his Prodromus 

 of a new classification of shells, laying down, more 

 precisely, the generic characters, and establishing 

 many new genera, and still continuing the old divi- 

 sion into univalves, bivalves, and multivalves. Up to 

 this time, Lamarck does not seem to have profited 

 much by the labours of his predecessors towards the 

 establishment of a natural conchyliological method, 

 but acknowledges that he has adopted the principles 

 and views of Bruguiere. Late in 1799, Cuvier pub- 

 lished a table of the divisions of the class of mollusca, 

 at the end of the first volume of his Lessons of Com- 

 parative Anatomy. We see, in this, that Cuvier had 

 derived light from the Prodromus of Lamarck. In- 

 deed, these two great naturalists, by their successive 

 works, seem to have afforded light alternately to 

 each other for a number of years. In 1801, Lamarck 

 published his Animaux sans Vertebres, in which, 

 not confining himself entirely to the shells, he has, 

 like Cuvier, paid attention also to the animals. From 

 this period until 1822, when he finished publishing the 

 second edition of Animaux sans Pertebres, under the 

 title of Histoire naturelle des Animaux sans P'ertebres, 

 many authors,* both continental and British, had pub- 



* De Ferussac, Draparnaud, Uenys.de Montford.de Ro. 

 issy, Bosc, Perron, Leswrues, De Blainvillc, D'nneril, Cha- 

 iiiisso, Kulil, Yon Midi, Von Pichtel, Megerle.Oken, Ratines. 

 que, Desiuarest, Savigny, Leach, Olfers, Sowerby, Schwei- 

 ger, Swaiuson, Ranzani, Say. 



